Recovery without Backup. All Data Lost?

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1 An Overview and Field Report Igor Romansky Peter Jensch Trivadis GmbH, Stuttgart DOAG Regio-Treffen Stuttgart, July 21th 2016 BASLE BERN BRUGG DÜSSELDORF FRANKFURT A.M. FREIBURG I.BR. GENEVA HAMBURG COPENHAGEN LAUSANNE MUNICH STUTTGART VIENNA ZURICH

2 Agenda 1. Backup, Restore & Recovery 2. Some Hints 3. Tools and Support 4. Demo(s) 5. Summary

3 Backup, Restore & Recovery

4 Oracle Backup Concept (1) Oracle RMAN Backup User Managed Backup Some other Methods Full Backup Incremental 0 Incremental Cumulativ Differential Archive Backup Image Copy Block Change Tracking File Backup Offline-File Copy Online-File Copy BEGIN BACKUP END BACKUP Export Data Pump Snapshot Technologies Data-Unload SELECT into FILE

5 Oracle Backup Concept (2) RMAN Backup (Full) Incremental 0 Incremental 1 Archive Backup

6 Oracle Restore & Recovery (3) Full Database Restore and Recovery Tablespace Datafile SPFILE Controlfile Corrupted Block

7 Some Hints

8 Reasons of Media Corruption Server Power outage Hardware Failure OS Bugs Oracle Bugs Bug OS Utlilities can destroy ASM Disk Header Human Failures

9 Unable to Open Database SQL> startup ORACLE instance started. Total System Global Area bytes Fixed Size bytes Variable Size bytes Database Buffers bytes Redo Buffers bytes Database mounted. ORA-01157: cannot identify/lock data file 1 - see DBWR trace file ORA-01110: data file 1: '/u01/oradata/dbt01/system_dbt01_01.dbf'

10 Some Hints (1) USER Tablespace corrupted Offline drop all corrupted datafiles Open Database Drop corrupted Tablespaces UNDO Tablespace corrupted Switch to Manual Undo Management Set all Rollback Segments: _corrupted_rollback_segments Startup in restriced mode Drop corrupted Rollback Segments Drop Undo Tablespace SYSAUX Tablespace corrupted Create Controlfile without SYSAUX datafiles Recover database using backup controlfile Set both Parameters to TRUE _allow_resetlogs_corruption _allow_read_only_corruption Startup Database with open resetlogs

11 Some Hints (2) SYSTEM Tablespace corrupted Use DBVerify to check all other Oracle files Use RMAN, mount database and validate Backup Validate Database Set Manual Undo Management and set offline rollback segments _offline_rollback_segments=(_syssmu1$, ) Get the list of all rollback_segments from system datafile: cat system.dbf grep _SYSSMU Set Parameter to TRUE _allow_resetlogs_corruption _allow_read_only_corruption MOS Doc-ID: and

12 Tools and Support

13 Offline Data Unloading Tools. Unload Tools for later insert using SQL-Loader Tool Oracle DUL AUL (MyDUL) OracleODU jdul DUDE Parnassus Data RM License Only onsite $ per PC $ per DB? $ per DB Trial Version No Yes Yes No Yes Support No Yes Yes Yes Yes URL No mydul.net oracleodu.com ora600.be parnassusdata.com Documentation No Yes Yes? Yes Supported Versions All 8i 11g 7 12c 7 11g 9i 12c Programming Language? C++ C++ Java Java GUI? No No No Yes Country Netherland China China Belgium China

14 What the tools support (MyDUL) (1) Feature Overview Lost System Tablespace System Tablespace corrupted Tablespace dropped Data Files still exist Table truncated With reuse storage clause No object has reused the freed space Missing some data files for a given tablespace Corrupted Oracle ASM storage; Corrupted ASM disks and so on

15 What the tools support (MyDUL) (2)

16 What the tools support (PRM DUL3206) Feature Overview Graphical Interface (Java) RPM almost can recovery Oracle database on all operating system Source:

17 Not Supported TDE Secure LOBS (encrypted, deduplicated, compressed) Complax Datatypes (VARRAY, Spatial Data, Nested Tables) BFile

18 Demo (s)

19 Demo System-Tablespace Issue ORA-01157: cannot identify/lock data file 1 - see DBWR trace file ORA-01110: data file 1: '/u01/oradata/dbt01/system_dbt01_01.dbf' Unable to open database System Tablespace Datafile corrupted (Datafile Header)

20 Demo System-Tablespace Issue and little bit more Unable to open database ORA-01157: cannot identify/lock data file 1 - see DBWR trace file ORA-01110: data file 1: '/u01/oradata/dbt01/system_dbt01_01.dbf' System Tablespace and a little bit more SQL> select * from v$backup; FILE# STATUS CHANGE# TIME FILE NOT FOUND 0 2 NOT ACTIVE 0 3 NOT ACTIVE 0 4 NOT ACTIVE 0 5 FILE NOT FOUND 0 6 NOT ACTIVE

21 Summary

occurred Some good tools are availiable Application Knowhow must

22 Summary Check our Backup Concept Validate our Backup Concept (using External Knowhow ) TVD Backup If Database Corruption occurred Some good tools are availiable Application Knowhow must be availiable templates logging rman alerting parameters locking

23 Peter Jensch Principal Consultant Tel

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